Positron emission tomography (PET) is a high resolution, non-invasive, imaging technique for the visualization of human disease. In PET, 511 keV gamma photons produced during positron annihilation decay are detected. In the clinical setting, fluorine-18 (F-18) is one of the most widely used positron-emitting nuclides. However, complicated chemical reactions are needed to link F-18 with specific targeting vectors such as antibodies, antibody fragments, recombinant antibody constructs and longer-lived receptor-targeted peptides.
There is a need, therefore, for a method of effecting PET that does not rely on the F-18 isotope.